Automatic merge from submit-queue
proposals: Add Volume Hostpath "type" proposal
This is a continuation of #31384. It's related to #26816 as well.
The discussion in #31384 is worth reading and this proposal largely derives from my comments there.
cc @thockin @pmorie @saad-ali @kubernetes/sig-storage
cc @yujuhong since it talks briefly about kubelet doing more
cc @calebamiles I think we might need a "Feature" for this since it's an api change, though a minor one?